● Preheat the oven to 170°C/gas mark 3. Line a baking dish or brownie tray about 20cm x 30cm with baking paper.

● Melt the butter and chocolate in a small heatproof bowl fitted snugly over the top of a small pan of gently simmering water, making sure that its base doesn't actually touch the water. Stir carefully until melted and combined. Remove the bowl from the pan and beat in the cocoa powder. Pour into a large mixing bowl and set aside to cool slightly.

● Sift the flour into a bowl, add the salt and set aside. Whisk the eggs and both sugars together in another bowl until the sugars have dissolved.

● Stir the eggs into the chocolate mixture, then fold in the flour, ensuring it's completely combined to give a smooth, glossy batter.

● Pour the brownie mixture into the lined baking dish. Scatter the pecan halves generously across the surface and bake for anything between 15 and 30 minutes. When ready, a small crack will have formed around the edges of the brownie, and the centre will still be a little wobbly. A skewer pushed into the centre should come out with large, gooey crumbs on it, but not coated in wet batter.

● Leave the brownie to cool in its tin, then wrap the tin in cling film and chill overnight before cutting and devouring. This does demand serious willpower, but will give you the ultimate brownie – it's worth the wait.